On Thu, Feb 27, 2025 at 10:49:30AM -0800, Shyam Saini wrote:
> module_add_driver() relies on module_kset list for
> /sys/module/<built-in-module>/drivers directory creation.
>
> Since,
> commit 96a1a2412acba ("kernel/params.c: defer most of param_sysfs_init() to
> late_initcall time")
> drivers which are initialized from subsys_initcall() or any other
> higher precedence initcall couldn't find the related kobject entry
> in the module_kset list because module_kset is not fully populated
> by the time module_add_driver() refers it. As a consequence,
> module_add_driver() returns early without calling make_driver_name().
> Therefore, /sys/module/<built-in-module>/drivers is never created.
>
> Fix this issue by letting module_add_driver() handle module_kobject
> creation itself.
>
> Fixes: 96a1a2412acb ("kernel/params.c: defer most of param_sysfs_init() to
> late_initcall time")
> Cc: sta...@kernel.org
> Suggested-by: Rasmus Villemoes <li...@rasmusvillemoes.dk>
> Signed-off-by: Shyam Saini <shyamsa...@linux.microsoft.com>
> ---
> drivers/base/module.c | 13 +++++--------
> 1 file changed, 5 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/base/module.c b/drivers/base/module.c
> index 5bc71bea883a..218aaa096455 100644
> --- a/drivers/base/module.c
> +++ b/drivers/base/module.c
> @@ -42,16 +42,13 @@ int module_add_driver(struct module *mod, const struct
> device_driver *drv)
> if (mod)
> mk = &mod->mkobj;
> else if (drv->mod_name) {
> - struct kobject *mkobj;
> -
> - /* Lookup built-in module entry in /sys/modules */
> - mkobj = kset_find_obj(module_kset, drv->mod_name);
> - if (mkobj) {
> - mk = container_of(mkobj, struct module_kobject, kobj);
> + /* Lookup or create built-in module entry in /sys/modules */
> + mk = lookup_or_create_module_kobject(drv->mod_name);
> + if (mk) {
> /* remember our module structure */
> drv->p->mkobj = mk;
> - /* kset_find_obj took a reference */
> - kobject_put(mkobj);
> + /* lookup_or_create_module_kobject took a reference */
> + kobject_put(&mk->kobj);
> }
> }
>
> --
> 2.34.1
Acked-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>
